Entire Design Manual - Greenville County

Development shall be fitted to the topography and soils so as to create the least erosion potential;
Natural vegetation shall be retained and protected wherever possible;
Natural vegetation and non-structural methods shall be employed to the extent possible, for
streambank stabilization and erosion control in place of structural methods wherever possible;
Only the smallest practical area shall be exposed and then only for the shortest practical period of
time;
Erosion control practices such as interceptor ditches, berms, terraces, contour ripping, soil erosion
checks, and sediment basins shall be installed to minimize soil and water losses;
Temporary vegetation or mulching shall be used to protect areas exposed during the time of
development;
During and after development, storm water management practices shall be utilized to effectively
accommodate increased runoff caused by changes in soil and surface conditions, and to avoid
siltation of receiving streams;
Permanent vegetation and structures shall be installed in the development as soon as the weather
permits;
The design of outlet channels for the discharge of storm runoff shall be based on the runoff from
predicted storm frequency and shall include the vegetative or structural measures required to protect
the channel from scour and erosion;
Waterway stabilization structures such as drop structures, grade stabilization structures, and channel
liners shall be utilized to dissipate the energy of flowing water by holding the waterway slopes and
velocities within non-erosive limits;
Sediment basins and traps:
1) Sediment shall be removed mechanically when the sediment basin behind the temporary barrier
or the dam becomes filled, to an elevation shown on the plan or when the design capacity has
been reduced by 50%. The structure may be removed once stability is reached in the
development area;
2) A sediment basin or sediment trap may be required to be enclosed, in the discretion of the
Director, when necessary to ensure public safety;
Cut and fill slopes and other exposed areas shall be planted or otherwise protected from erosion
before the release of the permit obligations. The responsibility shall remain with the permittee or
owner until the planting is well established;
Fill may not be deposited beyond the mean high-water line unless the fill is used for marsh creation
or shore restoration and does not extend beyond the mean low-water line or the fill is placed behind
a structural shoreline erosion control device;
Calculations for design of all BMPs for sediment control must be included as part of the permit
application. Locations and timing of installation of sediment control BMPs must be shown on the
Sediment and Erosion Control Plan and included as part of the SWPPP;
Description of measures to prevent the discharge of solid materials, including building materials, to
waters of the State and the United States, except as authorized by a permit issued under section 404
Greenville County, South Carolina
January 2013 Storm Water Management Design Manual 3-14